Apparatus for use in slurry pumps

ABSTRACT

Apparatus ( 10 ) for use with a slurry pump, including a stationary part ( 12 ) which includes a processing chamber ( 13 ) having an inner side wall ( 16 ) and a central axis, an inlet ( 14 ) and an outlet ( 15 ) to and from the processing chamber ( 13 ) and a rotatable part ( 20 ) at least partially disposed within the processing chamber ( 13 ) and including an outer wall ( 21 ) which is spaced from the inner wall ( 16 ) of the processing chamber ( 13 ).

[0001] The present invention relates generally to apparatus suitable foruse with pumps such as for example centrifugal pumps for use in thepumping of slurries. By the term “slurries” is meant any liquidcontaining solid materials.

[0002] In some applications the solid, particulate matter or scaleparticles in a slurry is of such a size that it can cause clogging ordamage to the impeller of a centrifugal pump as the slurry passestherethrough.

[0003] An object of the present invention is to provide improvedapparatus which alleviates the aforementioned problem.

[0004] According to one aspect of the present invention there isprovided apparatus suitable for use with pumps, the apparatus includinga stationary part which includes a processing chamber having an innerside wall and a central axis, an inlet and an outlet to and from theprocessing chamber and a rotatable part at least partially disposedwithin the processing chamber and including an outer wall which isspaced from the inner wall of the processing chamber.

[0005] Preferably, the rotating part is configured so that the spacebetween the inner processing chamber wall and the outer wall of therotating part varies. In one preferred form of the invention therotating part is generally oval shaped when viewed in cross sectionalthough it will be appreciated that other suitable cross-sectionalshapes could be utilised.

[0006] As mentioned earlier the apparatus of the present invention issuitable for use with pumps such as centrifugal pumps. A typicalcentrifugal pump includes a pump casing having an impeller therein, apump inlet and a pump outlet.

[0007] In one preferred form of the invention the stationary part of theapparatus is operatively connected to or forms part of the pump inlet.For example, the stationary part may be in the form of a modified pumpinlet component or throat bush of the pump.

[0008] Preferably the inner wall surface of the processing chamber istapered inwardly in the direction of the central axis thereof from theinlet towards the outlet. In one preferred form the inner wall surfaceis generally frusto-conical in shape. It will be appreciated thatalternatively or in addition to the outer wall of the rotating part maybe inclined to provide for the tapering effect.

[0009] In one preferred form of the invention the rotatable part of theapparatus projects into the processing chamber through the outlet endthereof. The rotatable part may be in the form of a projection having atapering nose portion. Preferably the projection forms part of the pumpimpeller.

[0010] The apparatus may further include an upstream connecting sectionwhich operatively connects the delivery pipe for the slurry to thestationary part. Preferably the connecting section includes a taperingchamber which tapers outwardly from the end of the delivery pipe to thestationary part. Preferably the cross-sectional dimension of the inletto the processing chamber is about the same as the end of the connectingsection adjacent thereto.

[0011] Grooves or recesses may be provided in the inner wall surface ofthe processing chamber and/or the outer wall surface of the rotatablepart. Preferably the grooves or recesses are circumferentially spacedaround the wall surfaces and can extend generally in the directionbetween the inlet and outlet of the processing chamber, or be curvedrelative to the axis.

[0012] The operation of a preferred embodiment of the apparatusaccording to this aspect of the present invention will hereafter bedescribed. The slurry is delivered to the pump via a conventionaldelivery pipe or conduit where it enters the processing chamber of thestationary part of the apparatus via the inlet. The rotating part whichin a preferred form forms part of the pump impeller is rotating withinthe chamber. The tapered inner wall of the chamber funnels the slurrytowards the outlet of the chamber and into contact with the rotatingpart. The configuration of the rotatable part in combination with thetapered inner wall of the processing chamber causes large solids withinthe slurry to be broken down to a size where they can pass out of theoutlet and enter and pass through the pump. The edges of the grooves orrecess in the rotating part act as cutters on the solids in the slurryand cooperate with the grooves in the inner wall of the chamber to breakdown the solids in the slurry. The shape or contour of the rotatingelement has the effect of wedging and crashing the particles jammedbetween the stationary and rotating parts.

[0013] Preferred embodiments of the invention, will hereinafter bedescribed with reference to the accompanying drawings embodiments areattached and in those drawings:

[0014]FIG. 1 is a schematic sectional side elevation as a pump havingapparatus according to a preferred embodiment of the inventionassociated therewith;

[0015]FIG. 2 is a schematic sectional side elevation of apparatusaccording to one form of the present invention;

[0016]FIG. 3 is schematic side elevation of the apparatus show in FIG. 2with the impeller reduced by 90°;

[0017]FIG. 4 is an exploded perspective view of apparatus according tothe preferred embodiment of the present invention;

[0018]FIG. 5 is a partially and array perspective view of the apparatusshown in FIG. 4; and

[0019]FIG. 6 is a front elevation of the apparatus shown in FIGS. 4 and5.

[0020] Referring to FIG. 1 of the drawings there is shown a pump 50having a pump casing 51, an impeller 52 disposed within the pump casing51, the impeller 52 being operatively mounted to a drive shaft 54. Thepump 50 further includes a pump inlet or throat bush 55 through wheelwhich slurry enters the pump casing 51 and a pump outlet 57. Theapparatus 10 of the present invention forms part of the impeller 52 andthroat bush 55 of the pump.

[0021] As best seen in FIGS. 2 to 5 there is shown apparatus generallyindicated at 10 which includes a stationary part 12 having a processingchamber 13 therein which has an inner side wall 16, an inlet 14 and anoutlet 15 and a rotatable part 20 which is at least partially disposedwith the processing chamber 13 and includes an outer wall 21 which isspaced from the inner wall 16 of the processing chamber 13.

[0022] As best seen in FIG. 5 the rotating part 20 is generally oval incross section. As a result the distance between the outer wall 21 of therotating part 20 and the inner wall 16 of the stationary part varies.

[0023] As best seen in FIGS. 2 and 3 the inner wall surface 16 of theprocessing chamber 13 is slightly tapered inwardly in the direction ofthe central axis thereof from the inlet 14 towards the outlet 15.

[0024] As shown the rotatable part 20 of the apparatus projects into theprocessing chamber 13 through the outlet end thereof. The rotatable part20 is in the form of a projection 22 having a tapering nose portion 26.As shown the projection 22 forms part of the pump impeller 52.

[0025] The apparatus includes an upstream connecting section whichoperatively connects the delivery pipe for the slurry to the stationarypart 12. The connecting section includes a tapering chamber which tapersoutwardly from the end of the delivery pipe to the stationary part. Thecross-sectional dimension of the inlet to the processing chamber isabout the same as the end of the connecting section adjacent thereto.

[0026] Grooves or recesses 32 and 34 are provided in the inner wallsurface of the processing chamber 13 and the outer wall surface of therotatable part 20. The grooves or recesses 32 and 34 arecircumferentially spaced around the wall surfaces and extend generallyin the direction between the inlet and outlet of the processing chamber.The portions of each part between adjacent grooves or recesses formelements for breaking down, grinding or crushing which continue to acton the slurry being processed.

[0027] In operation slurry is delivered to the pump 50 via aconventional delivery pipe or conduit where it enters the processingchamber 13 of the stationary part 12 of the apparatus via the inlet 14.The rotating part 20 which forms part of the pump impeller 52 isrotating within the chamber 13. The tapered inner wall 16 of the chamberfunnels the slurry towards the outlet 15 of the chamber and into contactwith the rotating part. The configuration of the rotatable part incombination with the tapered inner wall of the processing chamber causeslarge solids within the slurry to be broken down to a size where theycan pass out of the outlet and enter and pass through the pump. Theedges of the grooves or recesses in the rotating part act as cutters onthe solids in the slurry and cooperate with the grooves in the innerwall of the chamber to break down the solids in the slurry. The shape orcontour of the rotating element has the effect of wedging and crushingthe particles jammed between the stationary and rotating parts.

[0028] Finally, it is to be understood that alterations, modificationsand/or additions may be incorporated into the various constructions andarrangements of parts without departing from the spirit or ambit of theinvention.

The claims defining the invention are as follows:
 1. Apparatus suitablefor use with pumps, the apparatus including a stationary part whichincludes a processing chamber having an inner side wall and a centralaxis, an inlet and an outlet to and from the processing chamber and arotatable part at least partially disposed within the processing chamberand including an outer wall which is spaced from the inner wall of theprocessing chamber.
 2. Apparatus according to claim 1 wherein therotating part is configured so that the space between the innerprocessing chamber wall and the outer wall of the rotating part varies.3. Apparatus according to claim 2 wherein the rotating part is generallyoval shaped when viewed in cross section.
 4. Apparatus according to anypreceding claim wherein the stationary part of the apparatus isoperatively connected to or forms part of a pump inlet of the pump. 5.Apparatus according to any preceding claim wherein the inner wallsurface of the processing chamber is tapered inwardly in the directionof the central axis thereof from the inlet towards the outlet. 6.Apparatus according to claim 5 wherein the inner wall surface isgenerally frusto-conical in shape.
 7. Apparatus according to anypreceding claim wherein the rotatable part of the apparatus projectsinto the processing chamber through the outlet end thereof.
 8. Apparatusaccording to claim 7 wherein the rotatable part includes a projectionhaving a tapering nose portion.
 9. Apparatus according to claim 7 orclaim 8 wherein the projection forms part of a pump impeller of thepump.
 10. Apparatus according to any preceding claim wherein theapparatus further includes an upstream connecting section whichoperatively connects a delivery pipe for the slurry to the stationarypart.
 11. Apparatus according to claim 10 wherein the connecting sectionincludes a tapering chamber which tapers outwardly from the end of thedelivery pipe to the stationary part.
 12. Apparatus according to claim11 wherein the cross-sectional dimension of the inlet to the processingchamber is about the same as the end of the connecting section adjacentthereto.
 13. Apparatus according to any preceding claim furtherincluding grooves or recesses in the inner wall surface of theprocessing chamber and/or the outer wall surface of the rotatable part.14. Apparatus according to claim 13 wherein the grooves or recesses arecircumferentially spaced around the wall surfaces and can extendgenerally in the direction between the inlet and outlet of theprocessing chamber, or be curved relative to the axis.
 15. Apparatussubstantially as hereinbefore described with reference to theaccompanying drawings.